Cool - right, glad to hear it's (somewhat) working again!
The machines should all be flashing their lights pretty much the instant the arcade appears... I suspect this might be a graphics card/driver issue...
Could I ask please, could you click Play, so it loads into the arcade. Then press Escape, to bring up the pause menu. Then move your mouse pointer to the very top-left of the screen and click very quickly three times. You should see a small flashing square up in the top-left as you click like so:
After clicking fast three times, it should bring up a grey screen that looks like this:
Could you please take a screenshot of this (by pressing Print Scr key on your keyboard), then paste it into a DM or reply post.
There might be something on that screen that gives me a clue why it's not working... thanks for your help, hopefully we can get to the bottom of this one